This invention relates to bulldozers which include resilient means to cushion the shock of impact applied to the bulldozer blade.
Various resilient cushioning means in association with a bulldozer blade or the like are known. For example, see U.S. Pat. Nos. 3,158,944; 3,265,380 (both assigned to the assignee of this invention); 2,986,827; and 3,279,105. Initially, it is to be noted that in each of these systems, single cushioning means absorb the impact on the blade over the full rearward travel of the blade. It has been deemed desirable under certain applications that the initial movement of the blade under impact be controlled by a cushioning means, with further movement of the blade under impact being controlled by additionally cushioning means, for better control of the impact applied to the blade. Clearly, none of the systems of the patents cited above include such characteristics.
Additionally, it has been found desirable to also include cushioning means for cushioning rebound actions of the blade. Such a feature adds to the overall proper control of cushioning of impact on the blade.